Producing ammonia.



1 ED STATES PAT OFFICE.

CARL BOSCH AND ALWIN MITTASOH, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY I ASSIGNOBS TO BADISCHE ANILIN 82; SODA FABRIK, OF LUDWIGSHAFEN-ON THE- SHINE, GERMANY, A CORPORATION.

PRODUCING AMMONIA.

NoDrawing.

To all whom it may concern:

- Be it known that we, CARL Boson and ALWIN MI'I'IASGH, subjects, respectively, of the King of Prussia and the King of Saxony, residing at Ludwigshafen-on-the- Rhine, Germany, have invented new and useful Improvements .in Producing Ammonia, of which the following is a specification.

For the production of ammonia from its elements, catalytic agents of various metals, such for instance as iron, cobalt, nickel, molybdenum and tungsten, have been proposed for use. The oxids of these metals are reducible by means of hydrogen and it has consequently been assumed that smali quantities of oxygen or water vapor, or other compounds yielding oxygen or water vapor, would not have any e ect on the re action. In fact several authors were of the opinion that only moist gases are capable of giving rise to ammonia (of. Ramsay and Young, J carnal of the Chemical Society, 45, 98 (1884), Woltereck, German Patent No. 146,712, page 1, lines 62 et seq Perman, Proceedings of the RoyaZ'Soez'ety, 76, 167 et seq. (1905), and Neogi and Adhicary, Zez'tschm'ft f'iir Anorgam'sche Ohemz'e, 69, 20s (1911)). y

We have now discovered that the best yields of ammonia, when employing such metal or metals as catalytic agent, can be obtained by passing a mixture of nitrogen and hydrogen, preferably in combining proportions, over such catalytic agent at temperatures not exceeding about 600 G, if

the mixture of nitrogen and hydrogen be practically completely freed from water or compounds capable of forming Water including for instance free oxygen, and this is the case both when the reaction is carried out under increased pressure and also at atmospheric pressure. For instance, the fine particles of water that are readily carried away by gas when bubbled through an aqueous liquid must be removed, and by the expression water we mean both water as such and in the form of vapor.

Specification of Letters Patent.

Application filed August 16, 1912. Serial No. 715,332.

Patented Oct. 30, 1917.

One method of treating the gas consists, for instance, in passing it, either at ordinary or at increased pressure, over heated palladium-asbestos and then over quicklime or the like. Other methods, however, can be used for freeing the gases from the undesired impurity.

Now what we claim is 1. The process of producing ammonia by freeing a mixture containing nitrogen and hydrogen irom water and compounds capable of glxing rise to water, and then passing the gas mixture over a catalytic agent containing a metal of the iron group, at a temperature not exceeding about 600 C.

2. The process of producing ammonia by freeing a mixture containing nitrogen and hydrogen from water and compounds capable of giving rise to water, and then passing the gas mixture over a catalytic agent containing iron, at a temperature not exceeding about 600 C.

3. The process of producing ammonia by passing amixture containing nitrogen and hydrogen over an efiicient drying agent, and then passing the gas mixture over a catalytic agent containing iron, at a temperature not exceeding about 600 C.

4; The process of producing ammonia by freeing a mixture containing nitrogen and hydrogen from water and compounds capable of giving rise to water and then" passing the gas mixture over iron at a temperature not exceeding about 600 C.

5. The process of producing ammonia. by 

